[PATCH] ASoC: qcom: lpass-cpu: Fix pop noise during audio capture begin

[PATCH] ASoC: qcom: lpass-cpu: Fix pop noise during audio capture begin

[Srinivasa Rao Mandadapu]

This patch fixes PoP noise of around 15ms observed during audio capture begin.
Enables BCLK and LRCLK in snd_soc_dai_ops startup call for introducing some delay
before capture start and clock enable.

Signed-off-by: Judy Hsiao <judyhsiao@chromium.org>
Signed-off-by: Srinivasa Rao Mandadapu <srivasam@codeaurora.org>
---
 sound/soc/qcom/lpass-cpu.c | 37 +++++++++++++++++++++++++++++++++----
 1 file changed, 33 insertions(+), 4 deletions(-)

diff --git a/sound/soc/qcom/lpass-cpu.c b/sound/soc/qcom/lpass-cpu.c
index c62d2612e8f5..3dcfc2f115a7 100644
--- a/sound/soc/qcom/lpass-cpu.c
+++ b/sound/soc/qcom/lpass-cpu.c
@@ -73,14 +73,28 @@ static int lpass_cpu_daiops_startup(struct snd_pcm_substream *substream,
 		struct snd_soc_dai *dai)
 {
 	struct lpass_data *drvdata = snd_soc_dai_get_drvdata(dai);
-	int ret;
+	struct lpaif_i2sctl *i2sctl = drvdata->i2sctl;
+	unsigned int id = dai->driver->id;
+	int ret = -EINVAL;
 
 	ret = clk_prepare_enable(drvdata->mi2s_osr_clk[dai->driver->id]);
 	if (ret) {
 		dev_err(dai->dev, "error in enabling mi2s osr clk: %d\n", ret);
 		return ret;
 	}
-	ret = clk_prepare(drvdata->mi2s_bit_clk[dai->driver->id]);
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		ret = regmap_fields_write(i2sctl->spken, id,
+						 LPAIF_I2SCTL_SPKEN_ENABLE);
+	} else  {
+		ret = regmap_fields_write(i2sctl->micen, id,
+						 LPAIF_I2SCTL_MICEN_ENABLE);
+	}
+	if (ret)
+		dev_err(dai->dev, "error writing to i2sctl reg: %d\n",
+			ret);
+
+	ret = clk_prepare_enable(drvdata->mi2s_bit_clk[dai->driver->id]);
 	if (ret) {
 		dev_err(dai->dev, "error in enabling mi2s bit clk: %d\n", ret);
 		clk_disable_unprepare(drvdata->mi2s_osr_clk[dai->driver->id]);
@@ -93,9 +107,23 @@ static void lpass_cpu_daiops_shutdown(struct snd_pcm_substream *substream,
 		struct snd_soc_dai *dai)
 {
 	struct lpass_data *drvdata = snd_soc_dai_get_drvdata(dai);
+	struct lpaif_i2sctl *i2sctl = drvdata->i2sctl;
+	unsigned int id = dai->driver->id;
+	int ret = -EINVAL;
 
 	clk_disable_unprepare(drvdata->mi2s_osr_clk[dai->driver->id]);
-	clk_unprepare(drvdata->mi2s_bit_clk[dai->driver->id]);
+	clk_disable_unprepare(drvdata->mi2s_bit_clk[dai->driver->id]);
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		ret = regmap_fields_write(i2sctl->spken, id,
+					 LPAIF_I2SCTL_SPKEN_DISABLE);
+	} else  {
+		ret = regmap_fields_write(i2sctl->micen, id,
+					 LPAIF_I2SCTL_MICEN_DISABLE);
+	}
+	if (ret)
+		dev_err(dai->dev, "error writing to i2sctl reg: %d\n",
+				ret);
 }
 
 static int lpass_cpu_daiops_hw_params(struct snd_pcm_substream *substream,
@@ -308,7 +336,8 @@ static int lpass_cpu_daiops_trigger(struct snd_pcm_substream *substream,
 				ret);
 
 		clk_disable(drvdata->mi2s_bit_clk[dai->driver->id]);
-
+		break;
+	default:
 		break;
 	}
 
-- 
Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.,
is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.

Re: [PATCH] ASoC: qcom: lpass-cpu: Fix pop noise during audio capture begin

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 491 bytes --]

On Thu, May 13, 2021 at 05:15:39PM +0530, Srinivasa Rao Mandadapu wrote:

> +	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
> +		ret = regmap_fields_write(i2sctl->spken, id,
> +						 LPAIF_I2SCTL_SPKEN_ENABLE);
> +	} else  {
> +		ret = regmap_fields_write(i2sctl->micen, id,
> +						 LPAIF_I2SCTL_MICEN_ENABLE);
> +	}

This commit doesn't remove the matching update in triger() so we'd have
two redundant updates.  I guess it's unlikely to be harmful but it looks
wrong/confusing.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [PATCH] ASoC: qcom: lpass-cpu: Fix pop noise during audio capture begin

[Srinivasa Rao Mandadapu]

Hi Brown,

Thanks for your review comments!!!

On 5/13/2021 7:01 PM, Mark Brown wrote:
> On Thu, May 13, 2021 at 05:15:39PM +0530, Srinivasa Rao Mandadapu wrote:
>
>> +	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
>> +		ret = regmap_fields_write(i2sctl->spken, id,
>> +						 LPAIF_I2SCTL_SPKEN_ENABLE);
>> +	} else  {
>> +		ret = regmap_fields_write(i2sctl->micen, id,
>> +						 LPAIF_I2SCTL_MICEN_ENABLE);
>> +	}
> This commit doesn't remove the matching update in triger() so we'd have
> two redundant updates.  I guess it's unlikely to be harmful but it looks
> wrong/confusing.

Yes, It's not harmful, as clk_prepare_enable is enabling clock only once 
but maintaining count.

As Some times in Suspend/resume Sequence not hitting startup/shutdown, 
but Trigger, so for maintaining

consistency not removed in trigger.

-- 
Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.,
is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.

Re: [PATCH] ASoC: qcom: lpass-cpu: Fix pop noise during audio capture begin

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 625 bytes --]

On Fri, May 14, 2021 at 12:20:46PM +0530, Srinivasa Rao Mandadapu wrote:
> On 5/13/2021 7:01 PM, Mark Brown wrote:

> > This commit doesn't remove the matching update in triger() so we'd have
> > two redundant updates.  I guess it's unlikely to be harmful but it looks
> > wrong/confusing.

> Yes, It's not harmful, as clk_prepare_enable is enabling clock only once but
> maintaining count.

> As Some times in Suspend/resume Sequence not hitting startup/shutdown, but
> Trigger, so for maintaining

> consistency not removed in trigger.

This at least needs some commenting so that it's clear, it looks buggy
at the minute.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]